Canon has been pushing ahead with vigor in the full frame mirrorless market, releasing a wide variety of competitive cameras and innovative lenses. The company shows no signs of stopping, as patents for more high-level lenses have appeared.
The patents detail specifications for three lenses: the RF 200mm f/2L IS USM, RF 300mm f/2.8L IS USM, and RF 500mm f/4L IS USM. All three of these lenses had direct counterparts in the EF lineup and were popular among sports and wildlife photographers who needed the combination of a lot of reach and a fast aperture all in a rugged package that offered high image quality, fast and accurate autofocus performance, and good image stabilization.
Beyond that, the EF 200mm f/2L IS USM found an unexpected second home among portrait photographers as a lens that could couple superbly thin depth of field with high levels of telephoto compression, creating images in which the subject practically popped off the screen. Of course, just because patents are filed does not mean the respective products will appear on the market, but I would be extraordinarily surprised if we do not see these lenses eventually, as they are widely used tools in sports, bird, and wildlife photography and would, without a doubt, be quite popular. Given that the 200mm f/2 is reserved mostly for indoor sports due to its shorter focal length, I suspect we'll see the 300mm f/2.8 and 500mm f/4 first.
I was expecting Canon to bring back 200/1.8 as with stabilised sensor there isn't need for the f2.0 IS I think.
On the other hand, dual-IS lets you get down to some incredibly slow shutter speeds, and the longer the lens, the less effective in-body IS becomes.
The question then is what is your plan and what are you going to shoot with the lens. Because in case of shooting sport and this lens was primarily designed for indoors sport then you wont be using slow shutter speed anyway. In terms of wildlife there would be two situations... One in which you shooting animals which you have to wait for and let them get close to you or second whare you shoot moving animals and you'll be on fast shooter speed. Then this lens will be used for portraits and even without IS with greater dof you'll be just fine
With the image quality of the modern zooms and high ISO mirrorless cameras, and the ability to quickly edit backgrounds, the need for wide aperture primes is becoming very little. Kai remarked on this very well in a recent review of a prime lens designed for portraits.
This lens is primarily designed for indoor sport. And if you're working professional you know that you rather invest in lens like this then spending extra time on front of computer... Of courses if you can afford the cost
Zdenek Malich, I own the F2 version.....and I bought due to an awesome portrait shooter that I followed for over 10 years used one for almost all his portrait shoots. To me, I use mine in Motorsports....its an awesome setup for night shots at tracks that their lighting is rather "lacking". I use it in the day time as well.....to get that great "bokeh" look. I gave up a while back...thinking that Canon wouldn't release a RF version......but ohhh now I need to start saving up for it!!!!
Hopefully the RF200 will be considerably lighter, like the new 600mm